The National Aquaculture Act of 1980 defines aquaculture as "the propagation and rearing of aquatic species in controlled or selected environments, including ocean ranching." The Act divides responsibility for most aquaculture research, regulatory and related activities among the Departments of Agriculture, Commerce, and Interior. Private aquaculture has grown rapidly and diversified in recent years; in the United States, aquaculture is dominated (80%) by catfish production.